D. c. voltage regulator



D.C. VOLTAGE REGULATOR 2 Sheets-Sheet 1 Filed May 25, 1958 June 6, 1961 J. H. POIRIER ETAL n.0. VOLTAGE REGULATOR 2 Sheets-Sheet 2 Filed May 25, 1958 mxo-x & wma-x OFDmPDO United States Patent O 2,987,664 D.C. VULTAGE REGULATOR Jules H. Poirier, San Diego, Arthur Shaw, Chula Vista, and John W. Campbell, Lemon Grove, Calif., assignors to Ryan Aeronautical Co., San Diego, Calif.

Filed May 23, 1958, Ser. No. 7 37,300 2 Claims. (Cl. 321-2) The present invention relates generally to voltage regulators and more particularly to a D.C. voltage regulator.

The primary object of this invention is to provide a D.C. voltage regulator in which unregulated D.C. voltage is converted to an A.C. square wave signal, the amplitude of which is controlled, the controlled square wave output then being rectified to provide a regulated D.C. voltage.

Another object of this invention is to provide a D.C. voltage regulator in which the square Wave power is controlled without changing the wave shape and simplifies circuit design, the high frequency on the order of l kc. to 2 kc. allowing the use of small transformers and other components so that the finished regulator is compact and light in Weight.`

A further object of this invention is to provide a D.C. voltage regulator in which the square wave amplifier is driven in a closed feedback loop by a portion of the output voltage.

Still another object of this invention is to provide a D.C. voltage regulator which will produce a regulated D.C. output of any desired potential, Within reasonable limits, from a low voltage, unregulated D.C. input.

Finally, it is an object to provide a D.C. voltage regulator of the aforementioned character which is simple and convenient to manufacture and use and which will give generally efficient and durable service.

With these and other objects definitely in view, this invention consists in the novel construction, combination and arrangement of elements and portions, as will be hereinafter fully ldescribed in the specification, particularly pointed out in the claims, and illustrated in the drawings which form a material part of this disclosure, and in which:

FIGURE 1 is a block diagram of the voltage regulator; and

FIGURE 2 is a schematic wiring diagram of one specific circuit corresponding to the block diagram.

Similar characters of reference indicate similar or identical elements and portions throughout the specification and throughout the views of the drawings.

Referring now to FIGURE 1 of the drawings, the circuit includes a source of constant D.C. reference voltage 10 which is fed to a mixer 12, the mixer also receiving a portion of the voltage across the output load 14. The mixed voltages are fed to a D.C. amplifier 16 together with the unregulated D.C. input voltage from a source 18, the resultant amplified voltage being passed to a square wave osciliator 20. The square wave output from the oscillator 2f? is amplified through a power amplifier 22 which has a closed loop feedback circuit 24, the amplified square output being converted back to D.C. l power through a rectifier 26 and filtered through a ripple reduction filter 2S to provide a regulated D.C. output.

FIGURE 2 shows a specific circuit arrangement which has been found particularly efficient, although it should be understood that other circuits may be used according to particular requirements. The compounded D. C. voltage from the D.C. amplifier 16 is supplied to the low power, transistorized, saturable reactor square wave oscillator 20 having a pair of transistors 30 and 32 connected in push pull, their emitters being connected to the input winding 34 of a saturable reactor 36, the D.C. voltage from amplifier 16 being applied to the center tap of the Patented June 6, 1961 ICC input Winding. The general circuitry and function of this type of square wave oscillator is well known in the art. The amplifier 22 is a push pull power amplifier having a pair of transistors 38 and 4l) whose emitters are fed from -a common center tap of the output winding 42 of the saturable reactor 36, the unregulated D.C. source 18 also being connected to this center tap, the collectors of said transistors being connected to opposite ends of the input winding 44 of an output transformer 46. This type of push-pull amplifier is also well known. However, in this instance, the bases of transistors 38 yand 40 are connected, through feedback loops 48 and 50 respectively, to the ends of the output Winding 42, said feedback loops including pickup windings 52 and 54 from the output transformer 46. Thus a portion of the amplified square wave power is fed back to the amplifier input and the amplifier `22 operates with a closed loop resulting in a high degree of stability. The output winding 56 of transformer 46 is connected to a conventional bridge rectifier 26 and ripple reduction filter 28 to provide a high power regulated D.C. output across the output load 14.

`In operation, the D.C. output voltage across the load 14 is compared by the mixer 12 to the reference voltage 10, the resultant algebraic voltage addition producing a changing error voltage which `fluctuates with the output voltage. This error voltage is amplified by the D.C. amplifier 16, so that the resultant amplified voltage decreases as the voltage at the load 14 increases, and is converted to A.C. square wave power by the oscillator 20 and amplifier 22. The amplified square wave power thus varies inversely with the output load voltage and, when rectified, consequently stabilizes the D.C. output of the circuit. The closed feedback loop of the amplifier 22 increases the circuit stability and, the greater the closed loop gain, the less the circuit has to compensate for unregulated supply voltage. By adjusting the tap on the output load 14, the compounded reference voltage may be varied, so providing means for controlling the total voltage fed to the square wave oscillator 20 and consequently governing the final output.

The operation of this invention will be clearly comprehended from a consideration of the foregoing description of the mechanical details thereof, taken in connection with the drawing and the above recited objects. It will be obvious that all said objects are amply achieved by this invention.

It is understood that minor variation from the form of the invention disclosed herein may be made without departure from the spirit and scope of the invention, and that the specification and drawing are to be considered as merely illustrative rather than limiting.

We claim:

l. Means for obtaining a controlled square Wave output for a D.C. voltage regulator having a source of unregulated D.C. voltage; a regulated D.C. voltage output and a source of constant reference voltage with mixing means for mixing a portion of the D.C. voltage output with the reference voltage to obtain a composite voltage varying inversely with changes in said D.C. voltage output, said means comprising: a square wave oscillator having a pair of transistors connected in push pull relation; a saturable core reactor having an input winding and an output winding; said transistors having emitters connected to opposite ends of said input winding; said input winding having a center tap connected to said mixing means; an amplifier having a second pair of transistors connected in push pull relation; an output transformer having an input winding and an output winding; said second pair of transistors having collectors connected to opposite ends of said transformer input winding; said reactor output vfu'nding having a center tap; said second pair off transistors having emitters connected to said last men-` tioned center tap and to said source of unregulated D C. voltage; said transformer having pick-up windings; said second pair of transistors having` bases connected in closed feedback loops, through said pick-up windings, to opposite ends of said reactor output winding; and said transformer output winding being connected to said regulated DC. voltage output throughv rectifying means for changing the alternating current in said transformer output winding to direct current.

2. A D.C. voltage regulator comprising: a source of unregulated D.C. voltage and a regulated D.C. voltage output; a source or constant reference voltage; a square Wave oscillator having a pair of transistors connected in push pull relation; a saturable core reactor having an input Winding and an output winding; said! transistorshaving emitters connected to opposite ends of said input winding; mixing means for mixing a portion of theD.C. Voltage output with said reference voltage to obtain a composite voltage varying inversely with changes in said D.C. voltage output; said input winding having a center tap connected to said mixing means; an amplier having a second pair ofA transistors connectedl in push pull relation; an output-transformer having an input winding and an output winding; said second pair of transistors having collectors connected to opposite ends of said transformer input winding; said reactor output winding having a center tap; said second, pair of transistors havingemitters conw nected to said' last mentioned center tap and; to said source of. unregulated DC., voltage; Said; t.ratlstorrner` having pick-up windings; said second pair of transistorshaving bases connected inf closed feedback loops, through said pick-up windings, to opposite ends of said reactor output winding; and rectifying means coupled between said transformer output winding and said-regulated'DC; voltage output.

Referencesv Citedl in the iile of this patent UNITED STATES PATENTS 2,573,402 Chapman Oct. 30; 1,951 2,683,852 Sampson July 1319-54 2,785,236 Bright et al Mar. l2, 1957 2,791,739 Light M ay.71957 2,848,614 Lyons Aug. 19, 1958' 2,849,614 Royer et al Aug. 26', 11958 

